The development of highly automated cameras capable of being folded into a thin, compact shape suited for convenient carrying as described, for instance, in U.S. Pat. Nos. 3,750,551; 3,744,385; 3,731,608; and 3,714,879 has generated a corresponding requirement for a relatively inexpensive disposable battery power supply. To provide the somewhat specialized power requirements for the instrumentalities of the camera while at the same time maintaining requisite compactness, a flat, multicell primary battery is required which exhibits a low internal impedance to produce a relatively high current output for powering motor driven film processing and reflex optics, cocking assemblies along with shutter control features. During this powering activity, the battery is called upon to maintain predetermined voltage levels required to operate integrated logic control circuits.
For purposes of consumer convenience as well as the maintenance of the requisite compactness of the camera system, as described in U.S. Pat. No. 3,543,662, the flat batteries preferably are pre-packaged within a film-laden cassette assembly and generally take the area dimensional configuration of one film unit therewithin. Accordingly, a disposable power supply is combined with a disposable film cassette thereby permitting requisite compactness and thinness of the resultant camera system while assuring a continuously replenished or fresh and active power supply.
To remain practical within the above-described camera system, the multicell flat batteries must be structured to exhibit an assured or reliable shelf life concomitant with their copackaged film unit. Such reliability is mandatory inasmuch as any dysfunctions on the part of the battery component of the cassette assemblage well may result in the wasting of an entire film package. When considered from the viewpoint of high volume manufacture and packaging, however, an inexpensively assembled flat laminar multicell battery format necessarily is somewhat delicate. For instance, the peripheral borders of the sheet-type electrochemically active components of the battery must both be sealed with a high degree of integrity and the electrically conductive components thereof must be protected from shorting effects and the like. Further, the overall structuring of the components of the batteries must combine or interrelate to provide both the noted output characteristics as well as a requisite shelf life. The selection of component materials, their shapes, interrelational geometries and the techniques of their practical assembly has continued to require improvement. A succession of design alterations to structure, material or assembly may remain somewhat subtle, but also may combine to achieve needed performance.